Conventionally, for the purpose of reducing power consumption, there are multiprocessor systems that have a function of stopping and resuming power supply to each processor.
As a technique for reducing the power consumption of a multiprocessor system, for example, a technique may be considered in which the power of a processor is turned on or off based on whether or not a thread is executed by the processor. Generally, when power of a processor transits from the On state to the Off state or from the Off state to the On state, a current corresponding to the electrostatic capacitance of the processor flows, and accordingly, the frequency of transitions between the On and Off states is preferably not high from the viewpoint of low power consumption. However, according to such a technique, in a case where the number of threads (hereinafter, referred to as executable threads) that are executable instantly frequently changes, the frequency of transitions between the On and Off states of power increases, whereby there are cases where the power consumption increases.
In addition, it takes some time for the transition between the states of power. Thus, in a case where a time in which the On state or the Off state of the power is maintained should be short. If the time for transiting between the On state and the Off state is long, the performance of the multiprocessor system is lowered.